Teflon moves from the kitchen into the streets as Du Pont Co. finds an advertising use for the coating. A Citrus Connection bus in Lakeland, Fla., was the first to use a Teflon overlay on an ad. The 700-square-foot wraparound ad, designed by Graphic Systems Installers, featured oversize views of cars for the Robert G. Waters dealership. Du Pont says a Teflon-coated ad provides a higher-gloss image and protects it from scratches and weather, as well as making it easier to clean off graffiti. The process is available internationally.